Fountain pen



July 5, 1955 E. vv. RIQKMEYER FOUNTAIN PEN 2 Sheets-Sheet l Filed Aug.24, 1948 I N VEN TOR. me);

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FOUNTAIN PEN Filed Allg. 24, 1948 2 Sheets-Sheet 2 w.. than lgatented.italy 5,

FQUNTAIN PEN Ernst W. Rickmeyer, Prospect Heights, lll., assigner to TheParker Pen Company, .Milesi/ille, Wis., a corpo1 radon of WisconsinApplication August 24, $48, Serial No. 45,323

1 Claim. (Cl. 1120-50) This invention relates generally to fountain pensand has to do particularly with capillary feed and filler meanstherefor. It also relates to a sintered metal especially well adaptedfor use in forming a capillary element for a fountain pen.

An object of this invention is to provide a improved fountain pen.

Another object is to provide an inexpensive capillary fountain pen.

.Another object is to provide a capillary fountain pen having acapillary reservoir element wherein- (a) The reservoir element is ofporous sintered metal, and more particularly sintered metal whose massdefines relatively large interconnected pores but is itself providedwith interconnected pores smaller than the first pores;

(b) The nature and size of the pores may be closely predetermined toinsure desirable capillary characteristics, and controlled to providepores of concave shape and rough surfaces;

(c) The sntered metal of the reservoir element is free of scale andother foreign matter;

(d) The surfaces defining the pores exhibit a high degree of Wettabilityby aqueous inks;

(e) The sintered metal has substantial mechanical strength.

Other objects and advantages of my invention will appear from thefollowing description taken in connection with the appended drawings,wherein:

Figure l is a longitudinal sectional View of one en bodiment of afountain pen constructed in accordance with my invention;

Fig. 2 is an exploded fragmentary perspective View of the feed bar andcapillary filler and reservoir element of the pen of Fig. l;

Fig. 3 is an enlarged transverse sectional view taken along line 3 3 ofFig. l;

Fig. 4 is an enlarged transverse sectional view taken along line 4 4 ofFig. l;

Fig. 5 is an enlarged transverse sectional view taken along line 5 5 ofFig. l;

Fig. 6 is a fragmentary perspective view of a modified form of capillaryfiller and reservoir element having an integral feed bar;

Fig. 7 is a reproduction of a photomicrograph of a specimen of materialmade in accordance with my invention; and i Fig. 8 is a reproduction ofa photomicrograph of the specimen of Fig. 7 but turned approximately 90.

In accordance with the present invention, a fountain pen is provided inwhich at least a portion of the structure by which the ink is stored anddelivered to the writing element is defined by an element formed ofporous sintered metal adapted to retain the ink therein by capillaryattraction. Such sintered metal element is formed as an integral metalbody provided with interconnected pores of such size that they draw inink by capillary action and retain the ink therein by capillary actionexcept when it is withdrawn in writing.

new and it will be understood that my invention, in certain of itsaspects, is not limited to fountain pens but, as will be seen as thedescription proceeds, it lends itself to other applications wheregenerally similar capillary charactcristics are desired.

Referring now particularly to Fig. l of the drawings, the pen comprisesa hollow barrel or casing formed of suitable material such as a plasticor a metal, which barrel preferably includes a rear barrel section 20and a forward barrel section or shell member 2 secured to the rearbarrel section 20 as by an externally threaded nipple 22. The barrel Ztland shell Z1 together define a chamber 23 terminating in a reduced bore25 at the forward end of the shell 2l and adapted to accommodate,respectively, a filler element 24 and a writing element Z6 both of whichwill be described more fully hereinafter. T he writing element 26preferably takes the form of a nib having a generally cylindrical splitbody portion 27 terminating in a tapered writing tip which is formedwith a longitudinally extending slit 28 in a customary manner.

The filler element 24, so called for convenience, serves as a capillaryfiller and ink storage element, or reservoir element.

The filler element 24 is formed of porous sintered metal which isdescribed more fully hereinafter and which defines a large number ofinterconnected cells or pores of capillary size. The sintered metalelement may be formed as a single member of elongate, preferablygenerally cylindrical form, although for convenience in making it, lprefer to form it as two semi-cylindrical members 3l) which areassembled in firm face-to-face relation to provide a cylindrical member.For purposes of venting the filler element, a vent passage 3l isprovided which extends longitudinally and, preferably, throughout theentire length of such element. This passage is of greater than capillarysize in order to permit air to pass freely therethrough, but into whichpassage ink ordinarily will not enter.

The filler element 2li preferably is enclosed in a casing which formstherewith a unitary cartridge 32 which may be inserted into or removedfrom the pen barrel as a unit. The casing preferably takes the form of acylindrical shell or sleeve 33 which fits closely around the llerelement 24, and end plugs 34 and 35 secured to the sleeve as by crimpingthem into the sleeve as indicated at 36 and 37, respectively. Theforward end plug 34 is formed with a bore 33 extending therethroughadapted to receive a feed bar 39. The rear end plug 35' is formed with acentral opening ill registering with the vent passage 3l and withfilling openings il communicating with channel slots 42 extending acrossthe inner face of the plug 35 and communicating with the central opening46. The casing may be formed of silver, as is the filler element, aswill be brought out more fully later; the end plugs 34 and 35 may beformed of a suitable plastic.

The cartridge 32 is positioned in the barrel in a Suitable manner, as byabutting the forward end against a shoulder 43 provided in the barreland by clamping between a shoulder 4S formed in the barrel and thenipple 22, a bead d@ formed on the sleeve 33.

While it will be understood that the filler element 24 may be employedwithout the casing just described, the casing serves several desirablepurposes. The casing prevents damage to the filler element both duringassembly with the barrel and when the rear barrel section is removed;moreover, the casing prevents smearing of ink on the interior of thebarrel and soiling of the hands when the rear barrel section is removed,as for the purpose of filling the pen from the rear end (as hereinafterdescribed). The casing also serves to retain the several sections of thefiller element in assembled relation, where the filler element is formedin several sections; in addtion, the casing provides convenient meansfor supporting the feed bar where the latter is formed separately fromthe filler element and also may serve to maintain the separate feed barin feeding relation to the capillary filler element. Furthermore, thecasing serves to reduce evaporation of ink from the filler element.

The capillary spaces within the filler element 24 are connected in inkfeeding relation to the nib slit 28 by the feed bar 39 which, inaccordance with the present invention, is formed of sintered metalpreferably similar to the metal from which the filler element 24 isformed. The feed bar is of generally cylindrical shape and preferably isprovided with a tapered forward end 46 to permit holding the pen at asuitable writing angle to the paper. The rear end of the feed bar 39extends through the opening 38 in the forward end plug 34 and firmlyabuts the forward end of the filler element 24 to place the capillaryspaces of the feed bar in inl; feeding communication with the capillaryspaces of the filler element 24. The nib 26 is of such size that itfirmly grips the feed bar 39 and is maintained thereon with the underface of the top of the nib in firm contact with the upper surface of thefeed bar so that the slitted portion of the nib is held in close contactwith the feed bar. Preferably, also, the nib is firmly held frictionallyin the bore so that the nib and feed bar are prevented from beingdisplaced during use. The bore 25 may be relieved above the slittedportion of the nib 25 to permit flexing of the nib, although, ifdesired, the nib may be firmly held against fiexing. In order to insurefirm contact between the slitted portion of the nib and thecorresponding surface of the feed bar, either the nib or feed bar may beformed with a slightly oval cross section so arranged that, when the nibis telescoped over the feed bar, the nib is distorted slightly to causethe upper portion to bear firmly against the corresponding portion ofthe feed bar.

The pen may be filled by inserting the Writing end in a supply of ink toa sufficient depth to immerse the forward portion of the feed bar in theink. Ink is drawn by capillary action into the feed bar 39 and fromthence into the filler element 24. As the ink rises in the capillaryfiller element 24, air which was in the capillary spaces is forcedtherefrom and passes out through the vent passage 31 and vent opening 49into the chamber 23 from which it escapes through a vent opening 47provided at a suitable location in the barrel. The pen also may befilled by inserting the rear end of the filler element in the inl: afterhaving removed the rear barrel section 20. The

rear end of the cartridge 32 is inserted in the supply of ink asufficient distance to immerse the rear of the ller element 24,whereupon by reason of the communication provided by filling openings 41and slots 42 ink enters the casing 32 and contacts the rear end of theller element 24. As ink rises in the filler element 24, air which was inthe capillary spaces is forced therefrom and into the vent passage 31,from which it is forced out at the bottom (rear) end of the cartridgeand bubbles up through the supply of ink.

Since the capillary cells or spaces in the filler element and feed barare interconnected, they constitute a plurality of passages extendingthroughout the filler element and feed bar. Ink, therefore, stands inthe filler element and feed bar in a plurality of interconnectedcontinuous columns, which are supported by the capillary attractionexerted by the capillary spaces.

The capillary spaces in the filler element are of such size as to liftthe ink to the top of the filler element when the pen is held in avertical position in filling. While this size may differ under differentconditions, excellent results have been obtained by employing a fillerelement having spaces of approximately 0.005" maximum wallto-wall size.The nib slit is of smaller width than the capillary spaces in the feedbar or the filler element and preferably is approximately 0.0015 inwidth. Accordingly, ink will be drawn from the feed bar 39 into the nibslit so that ink is maintained always in the nib slit and the pen isalways in condition for instant writing. Whenever ink is withdrawn fromthe nib slit, as in writing, further ink is drawn by capillary actioninto the nib slit from the feed bar and ink is drawn by capillary actionfrom the filler element into the feed bar. It will be understood, asthis description proceeds, that by reason of the nature of the sinteredmetal feed bar, the exterior surface is not microscopically smooth butis formed with innumerable hills and valleys, the latter of which aresupplied with ink by reason of being connected with the capillary cellsor pores within the porous metal. Ink therefore stands on the surface ofthe feed bar in pools formed by the valleys and by reason of thewettability of the metal may also form a film over the hills. Thus, theink, generally speaking, forms a film of varying thickness on thesurface of the feed bar. Inasmuch as the upper surface of the feed baris in close contact with the under surface of the slitted portion of thenib, ink is drawn from the film of ink which stands on the upper surfaceof the feed bar. Preferably the capillarity of the feed bar is greaterthan that of the filler element, and the capillarity of the nib slit isgreater than that of the feed bar.

Where, as in the above described embodiment of my invention, the pen isconstructed so as to permit rear end filling, and it is desired toemploy such method of filling, the forward, exposed surface of the feedbar may be sealed to prevent evaporation of ink therefrom and to preventsoiling the fingers or clothes of the user should they come in contacttherewith. Such sealing may be conveniently provided by burnishing thesurface to be sealed, this being readily accomplished inasmuch as thefeed bar is formed of metal which at its surface may be workedsufficiently by pressure to cause it to seal those pores which extendthrough the surface of the member.

V/hile I prefer to form the filler element 24 and feed bar 39separately, primarily because of convenience in sintering, these membersmay be formed integrally as illustrated in Fig. 6 of the drawings. Insuch case, the member 50 which is formed of sintered material,constitutes both the filler element of the capillary system and the feedbar or feed element. An integrally formed member of this construction isadvantageous in that the necessity of maintaining the abuttingrelationship between the feed portion and the reservoir portion iseliminated. The integral member 50, as will be understood, may beprovided with a longitudinally extending vent passage (not shown) whichextends throughout the reservoir portion from the rear end thereof to ator near the juncture of the reservoir portion and the feed bar portion.

The mass of the material forming the filler element is actually sinteredand resintered--small particles are sintered to form larger particleswhich are therefore porous, and the larger particles are themselvessintered to form larger pores, and the finished mass then has smallinterconnected pores distributed substantially uniformly throughout themetal mass and connected to the large pores. The small pores have amaximum wall-to-wall dimension which is only a fraction of that of theprincipal pores and the former may be as small as 1/10 the size of theprincipal pores.

ln practicing this process, I may employ any of the metals designatedhereinbelow and for forming capillary members for fountain pens, Iprefer to use silver. The metal is employed in the form of a finepowder, and preferably is sufiiciently fine to pass through a 325 meshsieve. The metal powder is mixed with a suitable lubricant such asstearic acid or a suitable stearate, and the mixture rolled out in alayer from approximately 0.010 to approximately 0020" thick on a smoothsurface defined by a refrac tory material, such layer being severalparticles thick. Where silver is employed, material thus in layer formon a plate or other refractory member is sintered at a temperature offrom around 550 C. to around 650 C. in the presence of normalatmospheric air for approximately 1/2 hour to agglomerate the particles.Where other metals than silver are used, it is important that suchsintering be carried out in a suitable atmosphere to insure that nodeposit is formed on the surface of the metal.

The sheet thus formed is broken up in a suitable manner to form porousparticles which are at least as coarse as 100 mesh particles and whichmay be as coarse as 2O mesh. In other words, the porous particles formedby breaking up the agglomerated sheet are from 3 to l0 times as large asthe powdered particles initially employed in forming the sheet.

It is preferred that the sintered metal member be formed of silver,because of the ease of sintering silver and the desirable wettability byinks of the types customarily used in pens. owever, other metals suchgold, nickel. tantalum or alloys thereof, and stainless steel aresatisfactory. Among the alloys which have been found satisfactory aregold alloys including gold-copper. gold-silver, and gold-silver-copperalloys; silver alloys including silver nickel, silver-nickel-copper, andsilver-nickel-copper-gola alloys; and nickel alloys includingnickel-gold, nickelsilver, and nickei-copper alloys. While an 1828stainless steel alloy may be employed, I prefer to employ one containinga somewhat higher percentage of nickel in order to provide a somewhatgreater wettability characteristic.

The porous particles thus produced are mixed intimately with a materialwhich serves initially to maintain the particles in a relatively openmass, which material is driven off during the sintering operation, andwithout adversely affecting the sintering operation, to leaveinterconnected pores or spaces of the desired size when the metalparticles are integrally joined as a result of the sintering operation.This added material is for convenience designated as a spacing material.For this purpose, I employ a solid material which will be driven olfduring the sintering operation in gaseous form or in the form of agaseous product or products resulting from the heating. This material isone which is driven off at a relatively low temperature and which willnot leave any deposit or residue on the metal. In order to permitintimate mixing between the filler material and the metal powder, theformer material is employed in finely powdered condition. One materialthat has been found to give excellent results as a filler material isammonium bicarbonate; but it is to be understood that any known materialhaving the essential characteristics mentioned may be employed.

The filler material is employed in sutiicient proportion and in suchdegree of fineness as will provide the desired pore size, and in apreferred process for forming a capillary element for a pen, I useapproximately 67.5%, by weight, of silver powder and 32.5%, by weight,of ammonium bicarbonate, although excellent results have been obtainedwithin the range of 60% silver powder and 40% ammonium bicarbonate to75% silver powder and 25% ammonium bicarbonate. Excellent results havebeen obtained by using ammonium bicarbonate of a size from i8 to +50mesh.

ln addition to the powdered metal and filler material, l prefer toemploy a lubricant for permitting ready molding of the powder mixture ina mold under pressure in order to form a member having the desired shapeand size. For this purpose, l include approximately 1%, by weight, of asuitable lubricant in the mixture, which upon heating will not leave anyundesirable residue. While various lubricants may be employed, inaccordance with known sintering practice, I prefer to use stearic acidor a suitable stearate such as zinc stearate, copper stearate, aluminumstearate or cadmium stearato. The lubricant is employed in finelypowdered form and preferably is substantially liner than the othermaterials with which it is mixed. The metal powder, filler material andlubricant are mixed or blended to effect as uniform as possible anintermixture.

.in the course aan@ The mixture is then molded under pressure to providea molded mass or blank having the shape desired in the finished articleand a size which upon sintering will produce an article of the desiredsize, taking into consideration the shrinkage resulting from thesintering operation, as will be well understood in the art. The mixtureis molded in accordance with known practice under a suflicient pressureso that the blank will retain its shape until the sintering operationhas been completed, and to compact the mass to bring the metal particlesinto mutual contact. In the preferred embodiment of my invention, amolding pressure of from 3 to 7 tons per square inch is employed. itwill be noted in this connection that the pressures employed aresubstantially lower than the pressures employed in conventionalsintering practice which are several times the pressures here employed.

The molded mixture or blank is sintered at a suitable temperature andfor a sufficient length of time to unite the particles integrally butwithout melting them. Also, of such heating, the spacing material isdriven off in gaseous form. Preferably the sintering is carried out at atemperature approximately 27s of the melting point of the metal and inthe present process where silver is employed as the metal, the sinteringis carried out at a temperature of from around 550 C. to around 650 C.for a period of approximately one hour. it will be understood, ofcourse, that where other metals titan silver are employed, thetemperature and time will be selected correspondingly to effect thedesired results. "i" he sintering preferably is carried out in anelectric furnace although other heating methods may be employed, as willbe understood. Where silver is employed as the metal, excellent resultshave been obtained by sintering in the presence of normal atmosphericair inasmuch as silver does not oxidize under such conditions. However,where other metals are employed which oxidize at the temperatures usedin sintering, a suitable inert atmosphere must be employed in accordancewith known practice in order that the surfaces (both external andinternal and especially the external surfaces) of the sintered metalmember will be free of any foreign deposit such as oxides.

lt should further be explained at this point that care should be takenthrough the process to insure that no deposit is formed on the metalwhich would reduce the Wettability. Accordingly, great care should betaken to insure that the starting materials are suiciently pure and freeof foreign matter and that during each phase of the process no foreignmatter is introduced which would cause an undesirable deposit on themetal surfaces.

I have found in practicing the above described process that it isimportant that the filler material be in a dry state both preliminary tomixing it with the other ingredients of the mixture and after the mixinghas been accomplished and the molding step performed. inasmuch asammonium bicarbonate is quite hygroscopic, it is ess al that even wherethis material is initially in dry condition, the various steps in theprocess be carried out without undue delay in order to preventabsorption of moisture by the ammonium bicarbonate and resulting adverseeffects.

I have found that the above described difficulties resulting from theuse of ammonium bicarbonate may be eliminated by employing in lieu ofsuch material a material which is not hygroscopic, whereby the severalsteps in the process may be performed at wider spaced intervals, ifdesired. l found that amorphous carbon may be used with excellentresults as a filler material. In addition to its non-hygroscopicproperties, carbon lends itself more satisfactorily to blending thanammonium bicarbonate.

The process above described may be practiced using amorphous carbon inlieu of ammonium bicarbonate. The silver powder may be of the same meshand in the same proportion and the carbon may also be of approximatelythe same mesh, although excellent results have been obtained usingcarbon powder of a size from i8 to +70 mesh. These materials are mixedwith the lubricant and molded as described. Likewise, the sintering iscarried out in a manner similar to that described. with the exceptionthat the mixture is maintained at the sintering temperature for a longerperiod of time, and prelcra bly from two to three times as long as whereammonium bicarbonate is employed. The carbon, of course, does notsublime upon sintering but does form gaseous oxides which pass out ofthe metallic mass when the mass is sintered. It is essential that wherecarbon is employed, the sintering be carried out in an oxidizingatmosphere.

I have found also that a high melting point hydrocarbon wax selectedfrom those having melting points of from around 180 C. to around 200 C.may be employed as a spacing material in lieu of ammonium bicarbonate oramorphous carbon.

The metal resulting from the process thus far described containsinterconnected pores which are concave in shape and have rough irregularsurfaces. The pores are substantially entirely interconnected so thatthere are a minimum number of closed isolated pores or `oids in themetal. Moreover, the surfaces of the metal defining such interconnectedpores are clean and free of any deposit so that they exhibit a wettingcharacteristic substantially equivalent to that of the metal beforesintering. t will be understood, of course, that the surfaces of themetal which define the pores are very rough and irregular and for thatreason are somewhat more wettable than would be smooth or polishedsurfaces of the same material. The pores thus fill rapidly andcompletely.

The porosity of the material resulting from this process is very high,thus insuring a relatively large ink storage capacity in an element ofany particular size. For example, where 60% of silver and 40% ammoniumbicarbonate is employed as above described, the sintered metal has aporosity of around 82%; where 67.5% silver is used, the porosity isaround 7 8% and where 75% silver is used, the porosity is around 75%.

A photomicrograph of a specimen of material made in accordance with theprocess just described is reproduced in Figs. 7 and 8 of the drawings.Fig. 7 shows generally the faces of the particles, whereas Fig. 8 showsgenerally the edges, the specimen having been turned approximately 90.

Alternatively, excellent results may be obtained by omitting the spacingmaterial. In such case, the porous particles are mixed with a suitablelubricant, as for example stearic acid or a suitable stearate. Thelubricant may be employed in an amount of from around 0.25% to around 6%of the total mixture. The mixture is inserted in a cavity of suitableshape formed in a mold or other suitable container. The cavity isprogressively filled while vibrating the mold or container, eithercontinuously or intermittently, in order to suitably orient the porousparticles; that is to say, the porous particles are caused to arrangethemselves, in general, with their flat faces substantially parallel, Nomolding pressure is applied to the mixture but preferably a lightpressure is applied to lightly compact the particles in the mold, Themixture in the cavity is then sintered at a suitable temperature and fora suitable time to bond the particles into a unitary porous mass. Wherethe particles are formed from silver, the mixture is sintered in air ata temperature of from around 550 C. to around 650 C. for approximatelyone hour.

The metal produced by the foregoing process comprises a unitary porousrigid mass which is provided with relatively small, interconnected poresall of sustantially the same order of size and distributed throughoutthe mass. Such porous mass itself defines larger pores which are severaltimes-for example, up to ten times-the size of the small pores. Thelarge pores are of suitable capillary size to draw ink therein bycapillary action and to retain the ink by capillary action except whenwithdrawn, as in writing. Since the small pores are of substantiallygreater' capillarity than the large pores, ink will be drawn from thelarge pores into the small pores. It will be understood, of course, thatthe large pores, because of their nature, are directly interconnectedwith one another, and in addition, they are connected by means of thesmall pores in the porous mass. Accordingly, when ink is withdrawn fromthe sintered metal member, the large pores first are emptied andthereafter the small pores. Inasmuch as the small pores communicateextensively with the large pores, any ink which is in those portions ofthe large pores having a relatively small Wall-to-wall distance andwhich therefore exhibit a capillarity greater than the effectivecapillarity of the larger portions of the large pores, is drawn fromsuch smaller portions of the large pores by reason of the greatercapillarity of the small pores. Theretore, substantially no ink will beretained in the large pores against the capillarity established betweenthe writing element and the writing paper, even though the capillnrityof those portions of the large pores which have the smallestwall-to-wall dimension may be so great as to prevent withdrawal of theink therefrom were it not for the provision of the small pores. in otherwords, the structure of the metal of this embodiment of my inventionprovides a plurality of large interconnected channels to which areconnected interconnected channels of smaller size and greatercapillarity which latter channels serve effectively to exhaust the inkfrom all portions of the large channels.

The provision of the small pores serves still another desirablefunction, namely, that of imparting a high degree of wetta'oility of thelarge porcs which insures rapid filling of the member by capillaryaction. The small pores being of relatively great capillarity will liftthe inl; from the source of supply to a relatively great height withsubstantial rapidity. The ink thus stands at the orifices of such smallpores where the latter open into the large pores. Since the small poresare relatively closely spaced, the plural menisci at such orificesprovide closely spaced liquid surfaces along the walls defining thelarge pores. Therefore, when ink is drawn into the large pores, itcontacts such ink surfaces and bridges across the metal surface betweensuch ink surfaces and thus the ink rises more rapidly along the walls ofthe large pores than it would were the walls defined solely by the solidmetal. The small pores thus constitute pilot passages which are firstllecl with ink and which cause ink to stand at the surfaces of the largepores so that such latter surfaces will be rapidly wetted by the inkentering the large pores with the result that the large pores arerapidly filled. vl`hus, the small pores provide the initial liftingaction on the ink and the large interconnected pores permit rapid riseof a relatively large volume of ink in the porous metal member.

The mixture of porous particles and lubricant may be deposited in acavity formed in a refractory mold, in which case, upon sintering. themass of particles shrinks away from the Walls of the cavity and, whenthe sintering has been completed and the mold removed from the furnace,the sintered member may be readily removed from the mold. On the otherhand, where it is found desirable to enclose the molded member in ametal sheath or casing-11s, for example, in forming a unit such as thecartridge 32 described above-a somewhat different procedure may beemployed advantageously. In the latter case, instead of employing arefractory mold, a metal tube is provided which defines the cavity andinto which the powdered mixture is deposited, The metal tube is formedof a material to which the porous metal particles will be bonded duringthe sintering operation. Preferably, therefore, the tube is formed ofthe same material as the metal forming the particles. ln this process,the particles adjacent the metal tube will become bonded to the tube bythe sintering operation with the result that upon completion of thesintering operation a unitary structure is provided consisting of aporous metal mass enclosed within and bonded to a thin rnetal enclosingshell.

The expression sintered nz'etal as used herein wil1 be understood tomean a metal Jformed by sintering powdered metal. Except where otherwiseexpressly stated herein or indicated by the context of the description,it will be understood that the term metal includes not only a singleelemental metal out also alloys of two or more such metals.

In preparing each of tlie photomicrographs reproduced herein, specimensof the material made in accordance with the described process werefractured to expose the interior of the material and thephotomicrographs were taken at a magnication of 50 X.

I claim:

A fountain pen comprising a casing, a writing element mounted in thecasing, a capillary lier and reservoir element mounted in the casing andcomprising a member formed of sintered and re-sintered metal wherein there-sintered metal is composed of sintered particles, and wherein there-sintered metal has interconnected spaces between the sinteredparticles and each of the sintered particles has interconnected spacesof smaller size than the rst mentioned spaces, said spaces being definedby relatively rough wall surfaces, and means connecting said spaces incapillary ink feeding relation with said writing element.

References Cited in the file of this patent UNlTED STATES PATENTS2,157,596 Davis May 9, 1939 2,214,104 Hildabolt et al. Sept. 10, 19402,223,541 Baker Dec. 3, 1940 2,315,876 Sivil et a1. Apr. 6, 19432,325,550 Sager July 27, 1943 2,372,203 Hensel et al. Mar. 27, 19452,396,058 Rath Mar. 5, 1946 2,396,101 Hensel et al. Mar. 5, 19462,397,831 Bellamy Apr. 2, 1946 2,431,015 Andrews et al Nov. 18, 19472,432,061 Chesler Dec. 2, 1947 2,435,511 Rice Feb. 3, 1948 2,441,126Kurtz May 11, 1948 2,462,929 Zodtner Mar. 1, 1949 2,464,517 Kurtz Mar.15, 1949 2,522,553 Wittnebert Sept. 19, 1950 2,522,555 Bartell Sept. 19,1950 FOREIGN PATENTS 703,046 Germany Feb. 27, 1941

